This section is intended to introduce the reader to aspects of art that may be related to various aspects of the present disclosure described herein, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure described herein. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Industrial synthesis of hydrogen peroxide is predominantly achieved by using the Riedel-Pfleiderer process originally disclosed in U.S. Pat. Nos. 2,158,525 and 2,215,883. This well-known large scale cyclic production process of hydrogen peroxide makes use of the autoxidation of a 2-alkylanthrahydroquinone compound to the corresponding 2-alkylanthraquinone which results in the formation of hydrogen peroxide. In particular, the hydrogen peroxide is typically produced using a cyclical anthraquinone process (AO-process) comprising the hydrogenation of anthraquinone working solution in a catalytic reactor and the oxidation of the hydrogenated anthraquinone working solution by air in a multi-stage packed bed or sieve plate tower while simultaneously producing hydrogen peroxide in the organic stream, with the consecutive extraction of the hydrogen peroxide from the anthraquinone working solution by water in a multistage counter-current extraction column process. The organic solvent of choice is typically a mixture of two types of solvents, one being a good solvent of the quinone derivative (usually a mixture of aromatic compounds) and the other being a good solvent of the hydroxyquinone derivative (usually a long chain alcohol or cyclic ester). In addition to the main AO-process steps, there may be other ancillary process steps involved, such as the separation of the hydrogenation catalyst from the working solution; the recovery and polish purification of the anthraquinone working solution, the accompanying solvents, their recycle to the hydrogenator, and the recovery, polish purification and stabilization of the hydrogen peroxide product.
Accordingly, the conventional AO-processes and respective production plants are complicated and require many and large installments of equipment, a number of competent staff for maintenance of the equipment and operation of the main and ancillary process steps, and special safeguards to handle the resulting hydrogen peroxide in its usually high concentrations of 40 percent, and further distilled to concentrations of 50 to 70 percent. Hence, much management attention and frequent maintenance is required. Although one might assume that the AO-process may be performed on small-to medium-scale so as to merely satisfy local demand, in the state of the art it is still deemed that such processes require the use of many pieces of equipment, much management attention, and frequent maintenance, and that they are difficult to scale down and difficult to make such processes profitable.
Hence, what is needed is a method and system for producing hydrogen peroxide without the large capital costs associated with current large-scale to mega-scale production highly complex plants, and to develop a new process that would allow effective hydrogen peroxide production in portable and mobile units and small to medium size hydrogen peroxide production plant environments. In addition, the new process should be relatively simple to set-up, operate, start-up, or shut-down by an operator of any experience level without the need for high level technical training.